[Evaluation of Semantic Dementia Patient].

Semantic dementia (SD) is a clinical syndrome characterized by selective and progressive semantic memory impairment due to frontotemporal lobar degeneration (FTLD). Semantic memory disorders appear in every cognitive fields, be it language or recognition of familiar people and objects. Left-right asymmetry produces a distinctive clinical symptom of anterior temporal lobe atrophy. Progressive gogi (word-meaning) aphasia, i.e., word comprehension deficits with severe anomia, is prominent in left-dominant patients, whereas progressive prosopagnosia, i.e., difficulty recognizing familiar faces, is prominent in right-dominant patients. Loss of semantic memory of objects is observed in advanced stages of the disease. Behavioral symptoms are less prominent in the early stages; however, behavioral changes in patients with gogi aphasia are observed even in their initial visits. In addition to neuroimaging and neuropsychological evaluation of semantic memory, it will be useful if clinicians pay attention to behavioral changes of patients with gogi aphasia.